Axonal projections from the hypothalamus to the pituitary intermediate lobe in rats during ontogenesis: DiI tracing study

2005 ◽  
Vol 155 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Irina G. Makarenko ◽  
Michael V. Ugrumov ◽  
Andre Calas

1986 ◽  
Vol 113 (4) ◽  
pp. 471-478 ◽  
Author(s):  
R. J. Kemppainen ◽  
J. L. Sartin

Abstract. In order to examine regulation of pituitary intermediate lobe secretion, plasma immunoreactive (i)ACTH, cortisol, and α-MSH responses to iv bolus injections of CRF, quipazine maleate (serotonin agonist), isoproterenol (β-adrenergic agonist) or haloperidol (dopamine antagonist) were determined in conscious, unrestrained dogs. Endocrine responses to these test substances were also determined in dogs pre-treated with dexamethasone. Administration of one or more doses of each test substance resulted in significant elevations in plasma iACTH and cortisol concentrations. Only haloperidol injection caused significant increases in plasma iα-MSH. Following dexamethasone pre-treatment, plasma iACTH and cortisol increases in response to all test substances were considerably reduced or abolished. Dexamethasone did not alter baseline or haloperidol-stimulated plasma ia-MSH concentrations. However, infusion of bromocriptine mesylate (dopamine agonist) in combination with dexamethasone pre-treatment reduced the plasma iα-MSH response to haloperidol. We conclude that a dopaminergic pathway is important in the in vivo regulation of pituitary intermediate lobe activity in dogs.



1985 ◽  
Vol 260 (15) ◽  
pp. 8956-8963
Author(s):  
Y P Loh ◽  
B Myers ◽  
B Wong ◽  
D C Parish ◽  
M Lang ◽  
...  


2020 ◽  
Author(s):  
Veronica Moncho-Amor ◽  
Probir Chakravarty ◽  
Christophe Galichet ◽  
Ander Matheu ◽  
Robin Lovell-Badge ◽  
...  

AbstractLoss of P27 predominantly results in development of murine pituitary intermediate lobe (IL) tumours. We previously showed that the pleiotropic protein P27 can drive repression of the transcription factor Sox2. This interaction plays an important role during development of p27-/- IL tumours because loss of one copy of Sox2 diminishes tumorigenesis. Here, we have explored the cellular origin and mechanisms underlying melanotroph tumorigenesis in p27-/- IL. We show that IL hyperplasia is associated with reduced cellular differentiation, while levels of SOX2 increase in both stem cells (SC) and melanotrophs. Using loss-of-function and lineage tracing approaches, we demonstrate that SOX2 is required cell-autonomously in p27-/- melanotrophs and SCs for tumorigenesis. This is supported by studies deleting the Sox2 regulatory region 2 (Srr2), which is the target of P27 repressive action. Single cell transcriptomic analysis reveals that activation of a SOX2-dependent MAPK pathway in SCs is important for p27-/- tumorigenesis. Our data highlight different roles of SOX2 following loss of p27, according to the cellular context. Furthermore, we uncover a tumor-promoting function for SCs, which is SOX2-dependant. In conclusion, our results imply that targeting SCs, in addition to tumour cells themselves, may represent an efficient anti-tumoral strategy in certain contexts.



2000 ◽  
Vol 18 (7) ◽  
pp. 685-692 ◽  
Author(s):  
Bibie M. Chronwall ◽  
Scott A. Sands ◽  
Kenneth C. Cummings ◽  
Joan P. Schwartz


1993 ◽  
Vol 58 (3) ◽  
pp. 294-302 ◽  
Author(s):  
Elizabeth A. Young ◽  
David Bronstein ◽  
Huda Akil


1997 ◽  
Vol 761 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Peter J Crack ◽  
Dominic J Autelitano ◽  
A.Ian Smith


Endocrine ◽  
1997 ◽  
Vol 6 (3) ◽  
pp. 325-333 ◽  
Author(s):  
Scott A. Sands ◽  
Daniel S. Dickerson ◽  
Stephen J. Morris ◽  
Bibie M. Chronwall


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